Dolly-return device



J. DITSON.

DOLLY RETURN DEVICE.

APPLICATION FILED SEPT- 22, 1920.

1,386,769 a Patented Aug. 9, 1921.

a stares :rnssr. DITSON, or LITTLETON, coLoRAno, ASSIGNOR To IN RRsoLL-RA R COMPANY, or JERSEY our, NEW JERSEY, A coRroRArroN or NEW JERSEY. 1

DOLLY- ETURN :onvrcn.

Application filed September 22, 1920. Serial No. 412,048.

To all whom it may concern:

Be it known that I, Jnssn DITSON, a citizen of the United States, residing at Littleton, Arapahoe county, Colorado, have invented certain new and useful Improvements in Dolly-Return Devices, of which the following is a specification.

This invention relates to an automatic return for a fluid actuated dolly, such as used for instance in sharpening drill steels. The dolly is adapted to receive the impact blows of a piston hammer in a cylinder, and difficulty is experienced in preventing the springs or other devices for returning or retracting the dollies from breaking under the severe usage to which they are subjected.

The primary object of the present invention is to lessen the breakage of the springs or other return devices, and secure a simple, compact and strong return device yieldably controlled and actuated by fluid pressure.

To these ends the invention is illustrated in one of its preferred forms in the accompanying drawings, in which I Figure 1 is a longitudinal sectional elevation of a return device and so much of a dolly operating cylinder as will serve to illustrate the invention taken on the line 2-2 of Fig. 2, and

Fig. 2 is an end view of the apparatus.

Referring to the drawings, A represents a portion of a cylinder having a fluid actuated piston hammer B therein for imparting impact blows to the dolly C carried in the front head I) secured to the cylinder as by means of the usual side bolts E. Any suitable means (not shown) may be provided for supplying fluid pressure to the cylinder A for actuating the piston hammer B.

In order to provide a suitable and convenient mounting for the dolly return de vice, I have shown a bracket F secured to the lower portion of the cylinder A as by means of the bolts G and this frame is provided with suitable lugs H through which a pivot pin J extends secured in position as by means of the cotter pin K and forming a pivot for the dolly return member which in this instance is preferably in the form of a bent spring L having coils O encircling the pivot pin J and provided with an arm or arms P engaging the slot Q, in the dolly.

The other end of the spring is bent at an angle to the arms P to form an actuating arm R by means of which the dolly return member may be retracted.

Instead of supporting the arm R rigidly against a stop, have provided a fluid actuated device cooperating with said arm for yleldably resisting the movement of the sprlng member P and in this instance the fluid operated device consists of a plunger S movable within the fluid pressure cham ber T and adapted to bear against the actuating arm R of the member L. Fluid pres. sure may be supplied to the chamber T from the inlet passage U adapted to connect with the supply of the cylinder A, and a supply passage V in the cylinder connects with a supply passage W in the bracket F and leads to the port X in the chamber T.

In the operation of the device, the plunger S is maintained under fluid pressure in the chamber T while the piston hammer B is operating to impart blows to the dolly C, and each time that the dolly is driven forward, it will be automatically returned by the spring member L due to the resiliency of the spring and the pressure exerted by the plunger S on the actuating arm It of the spring. The liability of breakage is eliminated, or at least greatly reduced, be cause the resiliency of the spring is not alone depended upon. to return the dolly, but the spring is assisted by the fluid actuated plunger S.

I claim:

1. An automatic return device for a fluid actuated dolly, comprising a resilient member, pivoted adjacent the dolly and engaging the dolly, and fluid actuated means cooperatirlig with said member for retracting the dol y.

2. An automatic return device for a fluid actuated dolly, comprising a resilient member pivoted adjacent the dolly and having one arm engaging the dolly and another actuating arm extending at an angle to said first arm, and a fluid operated plunger adapted to bear upon said actuating arm and yieldingly resist the outward move- .ment of the dolly.

3. An automatic return device for a fluid actuated dolly, comprising a spring bent into Specification of Letters Patent. Pgmtgnted Aug 9 1921, j

the form of a bell crank and pivoted adjacent the dolly, one arm of the spring engaging the dolly and a fluid operated plunger adapted to press against the other arm of actuating arm extending at one angle to'the said dollyengaging arm, and fluid operated means cooperating with said actuating arm for rocking the spring member on its'pivot to return the dolly to initial position,

5. An automatic 'return device for a-fluid actuated dolly, comprising a member pivotedadjacent the dolly and having one arm engaging the dolly and another actuatingarm extendlng at an angle to said first arm,

and fluid operated means cooperating with said actuating arm for retracting the dolly.

v In testimony whereof I have signedthis v.l anssn DITSON:

specification. 7 

